Plant Pathology Flashcards
(14 cards)
What are the factors of the disease triangle?
1) a susceptible host plant,
2) a pathogenic agent (like a fungus or bacteria)
3) a conducive environment
Disease symptoms include:
Defoliation, stunting, wilting (all of these)
If a pesticide controls a plant pathogen, at what point in the disease lifecycle must the appropriate product be applied to achieve the most effective control?
Before plant symptoms appear/ as a preventive
Which of the following is a parasitic seed plant with orange tendrils?
Dodder
The term symptom always refers to a visible change in the plant, whereas the term sign refers to visible evidence of the pathogen. Which of the following would NOT be considered a symptom?
a leaf has a coating of a white fungus
Abiotic plant diseases can be caused by ?
1) unfavorable growing conditions
2) mineral deficiencies
3) air pollution
Fungi draw their sustenance from
other living organisms
Water molds are fungi that depend on wet conditions for growth and reproduction. Two very important diseases named for the genera of the water molds that cause them are
Pythium/ Phytophthora
. What are the optimum conditions for powdery mildew development?
warm days and cool, humid nights
What are characteristics of bacteria
Bacteria reproduce by splitting into two halves
Bacteria invade plants through wounds and natural openings
Bacteria can survive in soil (in some cases)
List three symptoms of plant disease
1) Defoliation
2) Stunting
3) Wilting
What shape do bacteria NOT take?
Cone shaped
What is the difference between a sign and a symptom?
Symptoms are visible reactions of a plant to a disease. Symptoms may contain a causative agent. Some examples would be leaf wilt, abnormal coloration, and defoliation.
Signs are the visible arts of the pathogen or its products seen on the host (plant), which can be used to identify the pathogen. Examples of a sign would be mushrooms growing on trees, white fungus coating a leaf, and droplets of bacterial ooze on a fruit tree twig.
